[en] 1 - Description of program or function: The Vehicle Code System (VCS) facilitates the calculation of radiation protection factors for a given vehicle; i.e. the ratio by which the free-field radiation is reduced due to the presence of the vehicle. VCS was constructed by linking together a discrete-ordinates air-transport calculation and an adjoint Monte Carlo vehicle dose-importance calculation. A tactical nuclear weapon of low-kiloton yield is detonated within a kilometer of a vehicle. The air-transport calculation determines the neutron and photon flux as a function of energy on a coupling surface surrounding the vehicle. The dose-importance calculation determines the effectiveness of particles at the coupling surface in contributing to dose at a detector position within the vehicle. 2 - Method of solution: VCS calculates protection factors for armored military vehicles by coupling a discrete ordinates calculation with an adjoint Monte Carlo calculation. The discrete ordinates calculation determines the flux on a coupling surface surrounding the vehicle. The Monte Carlo calculation calculates the effectiveness of flux at the surface in causing response in a detector adjacent to the crew members, i.e., the ^dose importance^. A coupling code folds the flux together with the dose importance, giving the dose response. The coupling code can also rotate the vehicle, move it to different distances from the source, and perturb the energy response of the detector. 3 - Restrictions on the complexity of the problem: None noted